Perhaps the law of unintended consequences has struck again. Or perhaps we really don't have a clue about what might be causing the earth's atmospheric temperature to rise. Either way an interesting new theory has popped in the study about what may be causing global warming. It seems that all the progress made to clean up skies over the last few years may be a contributing factor to more solar radiation reaching the ground. Skies over North American and European cities have gotten dramatically clearer since the 1960s. Aerosolized atmospheric particles have dropped by more than sixty percent in the last three decades in Europe while the amount of solar radiation has gone up. It now appears that the pollutants may have been directly reflecting radiation. Previously it had been thought that clouds seeded by the particles were reflecting the suns rays but current data is showing little impact on solar radiation on cloudy days. The new studies imply that the effect of reduced atmospheric pollution may actually account for half of the global warming effect. It looks like the more we learn the less we really know.